Self-stripping wire twister hook for wire balers



March 11, 1969 p. 1.. MAY mm. 3,4 31

SELF-STRIPPING WIRE TWISTER HOOK FOR WIRE BALERS Filed Oct. 21, 1966 F/GZ.

F/Gl.

INVENTORS PATRICK L. MAY 'W/LL/AM K. PA LSTON ATTY United States Patent 6 Claims ABSTRACT OF THE DISCLOSURE A self-stripping wire twister comprising a shaft rotatable about a fixed axis and a twister hook pivotally mounted on the shaft and corotatable therewith. The hook is normally disposed in a twisting attitude and is pivotally movable relative to the shaft to a stripping position.

This invention relates to a twisting mechanism of the general type used in hay balers and more particularly to an improvement in a twister hook for such a twisting mechanism.

The preferred embodiment of the present invention as disclosed herein contemplates that the novel twister hook be incorporated in a twisting mechanism of the type shown in the Raney Patent 2,513,967, issued July 4, 1950. In the twisting mechanism disclosed therein, a twister hook is used for twisting the ends of a strand of wire encircling a bale formed in a baler. At the conclusion of the twisting phase, a stripper finger is actuated forcing the twisted wire from the hook. The use of a stripper finger as the means for stripping the twisted wire from the hook is undesirable because it increases the complexity of an already complex mechanism. For example, the stripper finger must be actuated at precisely the right moment in the sequence of twisting operation. This requires modification of the other components of the mechanism in order that the stripper finger coordinate therewith. Furthermore, the stripper finger must be precisely adjusted to travel far enough out to dislodge the twisted wire from the hook. A general object of this invention is the provision of a self-stripping twister hook, that is, a hook that requires no additional equipment for dislodging the twisted wire therefrom, thereby reducing the complexity of the twisting mechanism and simplifying the twisting operation.

Another object of the present invention is to provide a wire twisting mechanism having a self-stripping twister hook.

A still further object is to provide a twister hook which is rotatable in a given plane for twisting and pivotable to a stripping position.

Still another object is to provide a rotatable twisting as sembly which is movable along the axis of rotation.

These and other objects of the present invention will become apparent to those skilled in the art as a preferred embodiment of the invention is disclosed in the following specification and claims taken in conjunction with the drawings in which:

FIGURE 1 is a sectional view, of the novel twister hook contemplated by the present invention showing the twister hook in the twisting position; and

FIGURE 2 is, similarly, a sectional view of the novel twister hook but shown in its stripping position.

The preferred embodiment of the present invention as disclosed herein shows the novel twister hook incorporated in a wire-twisting mechanism of the type shown in the previously mentioned Raney patent. However, it should be understood that this is for illustrative purposes only in order to show the environment in which the novel "ice hook operates, and that the novel features of the hook may be employed in other types of twister mechanisms.

A wire twister 10 constructed in accordance with the principles of the present invention is shown in FIGURE 1 and comprises generally a shaft 11 journalled to a frame 19, a bevel gear 13 rotatably mounted on an intermediate portion of shaft 11, and a twister hook 12 pivotally mounted on a lower end 11b of shaft 11. The intermediate portion of shaft 11 is serrated and fits into a cylindrical serrated section of bevel gear 13 so that the bevel gear 13 is corotatable with shaft 11 at a varying shaft length. (The bevel gear 13 corresponds to the bevel gear 61 shown in FIGURE 3 of the Raney Patent 2,513,967.)

A connector 15 is secured to end 11b of shaft 11 by a pin 16. From a downward depending member 15a of the connector 15 is pivoted a twister hook 12 which projects laterally with respect to the axis of the shaft 11. A pin 20 hinges the hook 12 to the member 15a and provides a hook pivotal axis which is oriented perpendicular to the direction of projection of the twister hook 12.

The hook 12 comprises a shank portion 17 and a beak portion 18, the beak portion being adapted to hook the Wire strands 28 in accordance with the operation of twister mechanism described in US. Patent No. 2,513,967.

The shank 17 is particularly characterized as having a radially projecting annular surface 17 which engages an annular surface 19a. formed in the frame 19. A rounded shoulder 17b is formed in a peripheral portion of the annular surface 17a at a diametric position opposite the direction of twister hook projection. The rounded shoulder 17b rollingly engages the annular surface 19a of the frame 19 as the hook pivots about the axis 20.

The shaft 11 is hollow having a cylindrical opening 21 therethrough. The shaft 11 is floatably carried by the housing 19 by means of a stud bolt 22 which telescopes into the cylindrical opening 21. The stud bolt 22 has one end 22a. disposed in the cylindrical opening 21 and carries a lower annular guide member 23 thereon. The periphery of the guide member 23 slidingly engages the surface of the cylindrical opening 21. An opposite end 22b of the stud bolt 22 is disposed above a top surface 1% of the frame 19 and carries a nut 24 which clamps a washer 25 into a forceful engagement with the surface 1%. At a point intermediate the washer 25 and the lower guide member 23 the stud bolt 22 slidingly carries an upper annular guide member 26. The upper guide member 26 closes the open end 11a of shaft 11 and provides a bearing surface for one end 27a of compression spring 27 which is mounted in the annulus between shaft 11 and the stud bolt 22. The opposite end 27b of compression spring 27 engages the lower guide member 23. Thus the upper guide member 26' moves axially along the stud bolt 22 and the lower guide member 23 remains stationary as the shaft 11 is extended from the bevel gear 13. The compression spring 27, acting between the two guide members 23 and 26, forces the movable upper guide member 26 upwardly relative to lower stationary guide member 23 into the normal twisting position as shown in FIGURE 1.

At the conclusion of the twisting operation, the twister hook 12 occupies its home position as shown in FIG- URE 1, wherein the beak 18 projects transversely with respect to the direction of movement of the formed bale encircled by the wire 28.

In a conventional baler the formed bale is forced rearwardly by a succeeding bale. Rearward movement of the formed bale increases the tension in the wire strands 28 since the wire is anchored to the pivot hook :12 by loop 28a. The wire in this position is unable to be stripped from the hook because the beak 18 is disposed transversely with respect to the direction of movement. At a predetermined wire tension the moment of force acting upon the twister hook 12 at the point of engagement of the loop 28a upon the beak 18 exceeds that acting on the twister hook 12 at a point coaxial with the axis of shaft 111. The imbalance of forces acting on the twister hook 12 causes it to pivot about the rounded shoulder 17b engagement upon the frame 19 pulling the shaft :11 down Wardly. Downward movement of the shaft 11 compresses the compression spring 27 between the movable and stationary guide members, 23 and 26. Pivotal movement continues toward the stripping position of FIGURE 2 until the wire loops 28a is stripped free of the beak 18. This disposition of the twister hook 12 permits the wire 28 to be stripped free of the beak 18 solely by rearward movement of the bale. The strength of the compression spring 27 is selected so that the twister hook 12 is maintained in the twisting position during the twisting phase.

It should be noted that the disposition of the hook 112 in the stripping position as shown in FIGURE 2 is removed axially and pivotally from the disposition of the hook 12 in the twisting position shown in FIGURE 1. Both the axial movement and the pivotal movement improves the disposition for stripping.

The preferred embodiment of the invention as presented herein shows the novel twister device as functioning in a twister mechanism described in US. Patent No. 2,513,967 for illustration only.

What is claimed is:

1. A self-stripping hook assembly comprising:

a shaft rotatable about a fixed axis, and

a hook pivotally mounted on said shaft and corotatable therewith, said hook being normally disposed in a twisting attitude and pivotally movable to a stripping position.

2. A self-stripping assembly for a wire baler, comprising:

a shaft rotatable about a fixed axis,

said shaft being movable downwardly along said axis;

and

a twister hook hinged to said shaft and swingable about a horizontal axis when swinging movement is limited by movement of said shaft along said axis.

3. A twisting mechanism for a wire baler comprising a frame, and

a wire twisting assembly journalled to said frame and including: a shaft, a drive means engageable with said shaft, a hook projecting laterally from One end of said shaft, said assembly being movable along the axis of said shaft between a wire twisting position and a wire stripping position; and bias means for biasing the said assembly in the said wire twisting position. 4. The twisting mechanism as recited in claim 3 wherein:

the said hook is pivotally connected to one end of the said shaft, the pivotal movement of the said hook being limited by said axial movement of said assembly. 5. The twisting mechanism as recited in claim 4 wherein:

the said hook engages the said frame in a nonpivotable relationship with the said shaft when the said assembly occupies the said wire twisting position, and the said hook is pivotable when the said assembly occupies the said stripping position. 6. The twisting mechanism as recited in claim 4 wherein:

the said bias means includes a compression spring concentrically mounted in said shaft, said compression spring having its opposite ends forceably engaging said drive means and said twisting assembly for biasing the said assembly in said twisting position.

References (Iited UNITED STATES PATENTS 1,040,786 10/1912 Seehafer 22 2,513,967 7/1950 Raney et al 10022 2,957,500 10/1960 Hollyday l49 BILLY J. WILH-ITE, Primary Examiner. 

